There are known prefab structural elements meant for housing constructions. They are provided in the shape of cubes with a lower surface meant for a floor, an upper surface meant for a ceiling and at least two lateral surfaces meant for walls. Such a cubic element can represent a quarter of the volume of a room and, by being assembled with other three similar elements, can form a complete room. These elements are provided with reinforcing ribs, of which same are so shaped that they can be used as supports for varied kinds of furniture, with clearance for windows and doors, as well as with channels for pipes and electric wires. They are also provided with means for mutual fixing of the elements to form a self supported assembly of rooms (U.S. Pat. No. 4,010,579).
A set of self supported prefabricated elements for modular housing construction is also known. This set consists of three basic elements, of variable sizes:
one inverted U shaped element, which represents the standard element for a room and it consists of two lateral walls and an overhead beam;
one inverted L shaped element, which represents a lateral wall and the ceiling and can be connected to the upper end of the lateral wall of the room; and
a parallelipipedic box shaped cell element opened on the part of the floor and provided with a clearance for the entrance door (U.S. Pat. No. 4,228,623).
These structural elements have the disadvantage they are expensive to fabricate, require transportation from the place of fabrication to the site, use significant energy and manpower, and require numerous loading, unloading and handling devices for positioning and assembling.
A set of structural elements for construction which can make walls, floors, ceiling and connection parts is also known. A modular multifunctional element of said set consists of a cross-shaped part and a H-shaped part, wherein the longitudinally oriented joining plugs, as tongues of the cross-shaped part, are arranged above and below corresponding cavities or grooves of the H-shaped part. Besides, the transversely oriented, shorter arms of the cross-shaped parts end straight and just above the longer arms of said H-shaped part, namely in the middle portion thereof. The above mentioned, multifunctional element can also be designated as a closing element having a single plug, as a T-connection, having three plugs, as well as a cross-shaped connection having four plugs. Special embodiments of the multifunctional element are provided with pierced holes through which pass reinforcing bars (U.S. Pat. No. DE 2,110,563).
A disadvantage of this set of structural elements for construction is that the multifunctional element has a rather complicated and labor consuming structure both to manufacture and to use.
Another disadvantage is that the reinforcing bars do not have any suitable means for tension thereof and thus for obtaining wall strength increase on building site. Beside there are no means for reinforcing corner connections.
A disadvantage of other known structural elements consists in that the joining with horizontal or vertical expansion joints need hydroinsulation and thermal insulation, using for this purpose asbestos sheets, mineral wool covered with polyvinylchloride, porous rubber tape, aluminum sheets, elastic materials and plastics tapes, so increasing the material and manpower requirements and the cost price.